How do I start Into the Valley of Death in CONTROL Resonant?

Progress into Recursions and Iterations, talk to Emily Pope twice in the Oldest House, then get Langston’s Apartment Key from Langston at the Central Field Panopticon.

How do I defeat Maria in Into the Valley of Death?

Fight her until she phases into walls, place the cat carrier at the red crack, then Call Cat three times when the red glow runs along the windows while standing on a lit vent.

What is the reward for Into the Valley of Death?

Untapped Catnip Toy, craftable in The Gap, plus materials and XP from the Maria fight.

CONTROL Resonant Into the Valley of Death

Quick answer: Into the Valley of Death is Langston’s Sinkhole side story: get Langston’s Apartment Key, find cat Alfred, load the feeder into the carrier, lure him (clear plants + piano), then use Call Cat three times to expose wall-phasing Maria. Reward: Untapped Catnip Toy. Unofficial companion.

You searched	Short answer
Into the Valley of Death	Langston → Sinkhole apartments → Alfred → Maria fight → Catnip Toy.
Langston key / apartment key	Talk to Langston at Central Field Panopticon during this quest.
Alfred / Maria	Alfred = cat in carrier; Maria = Hiss wall-phaser — Call Cat at glowing windows ×3.

How to unlock

Progress into Recursions and Iterations (after Act 1 / Enemy of My Enemy).
In the Oldest House, talk to Emily Pope, then talk again when she says she has one more thing — quest appears.
Central Field Office → Langston at the Field Panopticon → receive Langston’s Apartment Key.

Sinkhole → apartment

Evacuation Zone → Path to Sinkhole / laundromat entrance (same as Into the Sinkhole exit).
Through FBC checkpoint → Personnel Access platforms.
Follow yellow tape; speak to Ranger Dombrow in the lit apartment (remember this spot).
Continue to door marked 5 over the void → unlock with Langston’s key.

Load carrier & lure Alfred

Talk via the living-room cat feeder; inspect wallpaper claw marks + hallway blood for Langston.
Carry feeder to bedroom carrier → combine → pick up loaded carrier.
Follow toppled plants; place carrier on a bed in a lit bedroom with a running TV (near Dombrow’s apartment).
Play the piano / synth; remove all four potted plants from the rooms (toss them away).
Leave, wait for Langston’s radio that Alfred entered, return, pick up carrier.

Defeat Maria

Scream → Dombrow is dead — inspect body (Alfred didn’t kill him).
Follow Alfred’s meows / blood downward to Maria.
Phase 1: Fight her in the open until she flees into walls/windows.
Phase 2: Place carrier at the red glowing crack. When a red glow runs along the windows, stand on a lit vent and Call Cat when she’s one window away — hit this three times.
Finish her in the open; pick up carrier again.

Finish & reward

Place the carrier beside Dombrow’s body. Quest closes with Untapped Catnip Toy (craft in The Gap) plus zone XP / materials from the Maria fight. Crafting list: Artifacts.